The present invention relates to a machine for labeling containers around their complete circumference and having a driven rotating turntable with rotating plates that are positioned around its circumference, that accommodate the containers, and that, as they travel past a labeling station, are rotated at different individual speeds by means of a drive mechanism that includes roller cams and a recessed cam in order to adapt to the cross-sections of the different containers.
A labeling machine of this type is known from German OS No. 3 307 662. The speed of each rotating plate is adapted to the cross-sections of the containers in this machine by means of two mutually displaced toothed cams of a special design that operate in conjunction with star rollers that are fixed to the rotating plates. The toothed cams are designed to rotate the plates at different speeds within subsequent arcs to their path of rotation every time they rotate along with the turntable. The labeling station can be moved along the arcs of different speed. Cammed paths of this type are very expensive to manufacture, and displacing the labeling station along the comparatively long path demands a lot of space that is not readily available with labeling machines, as well as complicating the operation.
Labeling machines in which the speed of the rotating plates can be adapted to different container cross-sections by means of a toothed belt that operates in conjunction with several cogwheels of different diameter are also known (Krones-Canmatic brochure). This means of adaptation, however, demands an open design for the rotating-plate drive mechanism, and it is difficult and time-consuming to mount the belt.
German OS No. 3 127 309 discloses a labeling machine in which each rotating plate is fixed to a planet wheel that engages a sun wheel mounted concentric to the turntable. The sun wheel rotates and is synchronized with the turntable by a transmission with an adjustable rocker and an interchangeable wheel. The speed of the rotating plates can be adapted to various container cross-sections by changing the wheel to obtain a particular transmission ratio between the turntable and the sun wheel. A special wheel must of course be manufactured and kept on hand for each cross-section. Furthermore, the rocker must be readjusted every time the wheel is replaced, making this system of speed adaptation time consuming and attention demanding.
Finally, German OS No. 2 623 818 discloses a labeling machine with a lifting cam with an up-and-down motion that is converted into a plate rotation through a sloping-thread transmission. The lifting cam consists of several components that can be interchanged individually. Not only must a specific component be manufactured and kept on hand for each container cross-section, but, when new cam components are employed, the roller cams that operate in conjunction with the recessed cam for the mechanism that drives the rotating plate have to be threaded in, and the operator may not understand the process correctly, which can lead to severe breakdown.